Antenna gain question
 

On Thu, 03 Nov 2005 13:44:47 -0800, Jim Kelley
wrote:

If you wouldn't mind, try moving your Yagi a half wave forward or reverse.

Moving back one half wave:

EZNEC+ ver. 4.0

Vert Yagi in Ring of Sources 11/3/2005 2:37:02 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 1.655 V. at -135.94 deg.
Current = 0.1379 A. at -135.94 deg.
Impedance = 12 + J 0 ohms
Power = 0.2283 watts

Total applied power = 2000 watts

Total load power = 0.2283 watts
Total load loss = 0.0 dB


moving it such that its "driven" element is dead center to all
radiators (original configuration had the reflector in dead center):

EZNEC+ ver. 4.0

Vert Yagi in Ring of Sources 11/3/2005 2:40:58 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 1.584 V. at -22.13 deg.
Current = 0.132 A. at -22.13 deg.
Impedance = 12 + J 0 ohms
Power = 0.2091 watts

Total applied power = 2000 watts

Total load power = 0.2091 watts
Total load loss = 0.0 dB

73's
Richard Clark, KB7QHC

Antenna gain question
 

Richard Clark wrote:

On Thu, 03 Nov 2005 13:44:47 -0800, Jim Kelley
wrote:


If you wouldn't mind, try moving your Yagi a half wave forward or reverse.


Moving back one half wave:

EZNEC+ ver. 4.0

Vert Yagi in Ring of Sources 11/3/2005 2:37:02 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 1.655 V. at -135.94 deg.
Current = 0.1379 A. at -135.94 deg.
Impedance = 12 + J 0 ohms
Power = 0.2283 watts

Total applied power = 2000 watts

Total load power = 0.2283 watts
Total load loss = 0.0 dB


moving it such that its "driven" element is dead center to all
radiators (original configuration had the reflector in dead center):

EZNEC+ ver. 4.0

Vert Yagi in Ring of Sources 11/3/2005 2:40:58 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 1.584 V. at -22.13 deg.
Current = 0.132 A. at -22.13 deg.
Impedance = 12 + J 0 ohms
Power = 0.2091 watts

Total applied power = 2000 watts

Total load power = 0.2091 watts
Total load loss = 0.0 dB

73's
Richard Clark, KB7QHC

It looks like you'd have to use an array of non-coherent sources in
order to get rid of the phase cancellation effects (and really see
what's going on).

Thanks Richard.

ac6xg

Antenna gain question
 

On Thu, 03 Nov 2005 15:13:53 -0800, Jim Kelley
wrote:

It looks like you'd have to use an array of non-coherent sources in
order to get rid of the phase cancellation effects (and really see
what's going on).

Hi Jim,

Then it would be answering a different problem.

73's
Richard Clark, KB7QHC

Antenna gain question
 

Richard Clark wrote:

On Thu, 03 Nov 2005 15:13:53 -0800, Jim Kelley
wrote:


It looks like you'd have to use an array of non-coherent sources in
order to get rid of the phase cancellation effects (and really see
what's going on).


Hi Jim,

Then it would be answering a different problem.

73's
Richard Clark, KB7QHC

An antenna one, rather than an antenna +/- source one. Yes.

73, ac6xg

Antenna gain question
 

On Thu, 03 Nov 2005 15:13:53 -0800, Jim Kelley
wrote:
use an array of non-coherent sources

EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:39:03 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.002611 V. at -33.23 deg.
Current = 3.627E-05 A. at -33.23 deg.
Impedance = 72 + J 0 ohms
Power = 9.47E-08 watts

Total applied power = 1364 watts

Total load power = 9.47E-08 watts
Total load loss = 0.0 dB

then moved quarterwave:

EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:41:17 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.00676 V. at -110.1 deg.
Current = 9.389E-05 A. at -110.1 deg.
Impedance = 72 + J 0 ohms
Power = 6.348E-07 watts

Total applied power = 1364 watts

Total load power = 6.348E-07 watts
Total load loss = 0.0 dB

then moved backwards a quarterwave

EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:44:52 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.004604 V. at 29.97 deg.
Current = 6.395E-05 A. at 29.97 deg.
Impedance = 72 + J 0 ohms
Power = 2.944E-07 watts

Total applied power = 1364 watts

Total load power = 2.944E-07 watts
Total load loss = 0.0 dB

EZNEC+ ver. 4.0

Yagi in Ring of Rnd Sources 11/3/2005 5:48:14 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.07004 V. at 66.62 deg.
Current = 0.005837 A. at 66.62 deg.
Impedance = 12 + J 0 ohms
Power = 0.0004088 watts

Total applied power = 1364 watts

Total load power = 0.0004088 watts
Total load loss = 0.0 dB

moved back halfwave:

EZNEC+ ver. 4.0

Yagi in Ring of Rnd Sources 11/3/2005 5:51:43 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.09133 V. at -53.63 deg.
Current = 0.007611 A. at -53.63 deg.
Impedance = 12 + J 0 ohms
Power = 0.0006952 watts

Total applied power = 1364 watts

Total load power = 0.0006952 watts
Total load loss = 0.0 dB

(and really see what's going on)

Hmmm, at least 1000 times more response... so what's going on? (aside
from a possibly poor implementation of random). Trying to refine the
sources table with tighter random assignments is positively brutal
under EZNEC's primitive (read no) handling of columnar data.

73's
Richard Clark, KB7QHC

Antenna gain question
 

Very nice work. Dissapointingly ambiguous results.

Thank you.

ac6xg

Richard Clark wrote:

On Thu, 03 Nov 2005 15:13:53 -0800, Jim Kelley
wrote:

use an array of non-coherent sources


EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:39:03 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.002611 V. at -33.23 deg.
Current = 3.627E-05 A. at -33.23 deg.
Impedance = 72 + J 0 ohms
Power = 9.47E-08 watts

Total applied power = 1364 watts

Total load power = 9.47E-08 watts
Total load loss = 0.0 dB

then moved quarterwave:

EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:41:17 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.00676 V. at -110.1 deg.
Current = 9.389E-05 A. at -110.1 deg.
Impedance = 72 + J 0 ohms
Power = 6.348E-07 watts

Total applied power = 1364 watts

Total load power = 6.348E-07 watts
Total load loss = 0.0 dB

then moved backwards a quarterwave

EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:44:52 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.004604 V. at 29.97 deg.
Current = 6.395E-05 A. at 29.97 deg.
Impedance = 72 + J 0 ohms
Power = 2.944E-07 watts

Total applied power = 1364 watts

Total load power = 2.944E-07 watts
Total load loss = 0.0 dB

EZNEC+ ver. 4.0

Yagi in Ring of Rnd Sources 11/3/2005 5:48:14 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.07004 V. at 66.62 deg.
Current = 0.005837 A. at 66.62 deg.
Impedance = 12 + J 0 ohms
Power = 0.0004088 watts

Total applied power = 1364 watts

Total load power = 0.0004088 watts
Total load loss = 0.0 dB

moved back halfwave:

EZNEC+ ver. 4.0

Yagi in Ring of Rnd Sources 11/3/2005 5:51:43 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.09133 V. at -53.63 deg.
Current = 0.007611 A. at -53.63 deg.
Impedance = 12 + J 0 ohms
Power = 0.0006952 watts

Total applied power = 1364 watts

Total load power = 0.0006952 watts
Total load loss = 0.0 dB


(and really see what's going on)


Hmmm, at least 1000 times more response... so what's going on? (aside
from a possibly poor implementation of random). Trying to refine the
sources table with tighter random assignments is positively brutal
under EZNEC's primitive (read no) handling of columnar data.

73's
Richard Clark, KB7QHC

Antenna gain question
 

Richard,

It's not clear what aspect of your sources is "Rnd", but the fact that
they are monochromatic is still problematic.

73, ac6xg

Jim Kelley wrote:
Very nice work. Dissapointingly ambiguous results.

Thank you.

ac6xg

Richard Clark wrote:

On Thu, 03 Nov 2005 15:13:53 -0800, Jim Kelley
wrote:

use an array of non-coherent sources



EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:39:03 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.002611 V. at -33.23 deg.
Current = 3.627E-05 A. at -33.23 deg.
Impedance = 72 + J 0 ohms
Power = 9.47E-08 watts

Total applied power = 1364 watts

Total load power = 9.47E-08 watts
Total load loss = 0.0 dB

then moved quarterwave:

EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:41:17 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.00676 V. at -110.1 deg.
Current = 9.389E-05 A. at -110.1 deg.
Impedance = 72 + J 0 ohms
Power = 6.348E-07 watts

Total applied power = 1364 watts

Total load power = 6.348E-07 watts
Total load loss = 0.0 dB

then moved backwards a quarterwave

EZNEC+ ver. 4.0

Dipole in Ring of Rnd Sources 11/3/2005 5:44:52 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.004604 V. at 29.97 deg.
Current = 6.395E-05 A. at 29.97 deg.
Impedance = 72 + J 0 ohms
Power = 2.944E-07 watts

Total applied power = 1364 watts

Total load power = 2.944E-07 watts
Total load loss = 0.0 dB

EZNEC+ ver. 4.0

Yagi in Ring of Rnd Sources 11/3/2005 5:48:14 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.07004 V. at 66.62 deg.
Current = 0.005837 A. at 66.62 deg.
Impedance = 12 + J 0 ohms
Power = 0.0004088 watts

Total applied power = 1364 watts

Total load power = 0.0004088 watts
Total load loss = 0.0 dB

moved back halfwave:

EZNEC+ ver. 4.0

Yagi in Ring of Rnd Sources 11/3/2005 5:51:43 PM

--------------- LOAD DATA ---------------

Frequency = 70 MHz

Load 1 Voltage = 0.09133 V. at -53.63 deg.
Current = 0.007611 A. at -53.63 deg.
Impedance = 12 + J 0 ohms
Power = 0.0006952 watts

Total applied power = 1364 watts

Total load power = 0.0006952 watts
Total load loss = 0.0 dB


(and really see what's going on)



Hmmm, at least 1000 times more response... so what's going on? (aside
from a possibly poor implementation of random). Trying to refine the
sources table with tighter random assignments is positively brutal
under EZNEC's primitive (read no) handling of columnar data.

73's
Richard Clark, KB7QHC

Antenna gain question
 

On Fri, 04 Nov 2005 10:32:07 -0800, Jim Kelley
wrote:

It's not clear what aspect of your sources is "Rnd", but the fact that
they are monochromatic is still problematic.

Hi Jim,

You lost me on that curve. Monochromatic. The sources exhibit an
even distribution of varying phase in a random order. That was
tedious to accomplish, but achievable - in a group of 360 possible
degrees of phase, you eventually cover the field. On the other hand,
if you are suggesting that there needs to be an equally random
distribution of frequencies then that has its obvious issues of
practicability. What is the lowest frequency and what is the highest
frequency? That question has all the hallmarks of which infinity is
the biggest?

Anyway, I would surmise that if I could achieve both random phase and
frequency distribution, then the difference between a simple dipole's
response and that of a yagi antenna would be trivial. This would be a
given seeing that the parasitic elements would be virtually invisible,
rendering the "driven" element un-differentiable from the simple
dipole.

73's
Richard Clark, KB7QHC

Antenna gain question
 

Richard Clark wrote:


Anyway, I would surmise that if I could achieve both random phase and
frequency distribution, then the difference between a simple dipole's
response and that of a yagi antenna would be trivial.

Trivial would be a nice change.

This would be a
given seeing that the parasitic elements would be virtually invisible,
rendering the "driven" element un-differentiable from the simple
dipole.

i.e. what Roy said. But I think there's still more to it. I tried to
give the other Richard a hint about it but it didn't resonate.

73, ac6xg

Antenna gain question
 

Jim Kelley wrote:
i.e. what Roy said. But I think there's still more to it. I tried to
give the other Richard a hint about it but it didn't resonate.

Then obviously your XC didn't equal your XL.
--
73, Cecil http://www.qsl.net/w5dxp